What would you assume the shape of the demand curve for a drug like heroin would be? Certainly the demand for an addictive drug like that would be inelastic as a whole. However, it seems to me that beyond the market value that has been settled at, that the elasticity of demand would increase until it became wholy inelastic. But that's only beyond the market price. My logic is that, of course, people will be willing to pay almost whatever it costs to use heroin once they're addicted. So, prices will be competed up to a very high level straight off the bat. But they have to settle somewhere. There has to be a point beyond which even heroin addicts will be unable to buy heroin. So there is some limit. The fact that there is a settled market price should show that. It seems obvious that certain dealers should try to raise their prices above market price periodically, and the reason that these new prices don't set in as the market price is that the other dealers will under-cut them. If it were profitable for every dealer to raise up their prices, then they would do that. But that there's a settled market price would indicate there's a reason that the price isn't higher; namely that the price elasticity of demand begins to grow and become elastic. Does that make sense, or would others think that heroin's price could go up indefinately with a constant increase in total revenue?